The present invention relates to commercial ovens and, in particular, to heat exchangers for gas operated combination steam ovens.
Gas operated commercial ovens, such as combination ovens and other gas ovens, produce heat by delivering and burning gas in a burner tube. This produces heated flue gases that are directed to flow through a heat exchanger tube, eventually out of the oven, and are exhausted through a ventilation system. While the heated flue gases flow through the heat exchanger tube, heat is transferred from the heated flue gases to the material of the heat exchanger tube. A fan blows air across the heat exchanger tube, heating the air, and delivers the heated air into a cooking volume of the oven to cook the food.
Typical heat exchanger tubes are made from long lengths of round tubing that are bent into a looping configuration that is provided concentrically outside of a radial fan. Using round tubing provides low flow resistance for the flue gasses and allows the heat exchangers to be made using simple fabricating techniques and equipment such as rollers and benders that can typically form the entire looping configuration from a single piece of round tubing.